The name does not exist in the current context

[programmher]

I found this nifty code snippet and modified it with my values. Getting this error now: The name cblAuthorsList does not exist in the current context. Confused why since this is on my page. How do I resolve this error?

private void FindAllOfMyString(string searchString)

    {
        // Set the SelectionMode property of the ListBox to select multiple items.
        cblAuthorsList.SelectionMode = SelectionMode.MultiExtended;

        // Set our intial index variable to -1. 
        int x = -1;
        // If the search string is empty exit. 
        if (searchString.Length != 0)
        {
            // Loop through and find each item that matches the search string. 
            do
            {
                // Retrieve the item based on the previous index found. Starts with -1 which searches start.
                x = cblAuthorsList.FindString(searchString, x);
                // If no item is found that matches exit. 
                if (x != -1)
                {
                    // Since the FindString loops infinitely, determine if we found first item again and exit. 
                    if (cblAuthorsList.SelectedIndices.Count > 0)
                    {
                        if (x == cblAuthorsList.SelectedIndices[0])
                            return;
                    }
                    // Select the item in the ListBox once it is found.
                    cblAuthorsList.SetSelected(x, true);
                }

            } while (x != -1);
        }
    }


               
 <asp:CheckBoxList ID="cblAuthorsList" runat="server" Text='<%# Bind("Authors") %>' SelectionMode="Multiple" DataSourceID="odsAuthors" DataTextField="Name" DataValueField="Name" 
                                AppendDataBoundItems = "true" AutoPostBack="true">
                                <asp:ListItem Text="All Authors" Value="All Authors" />                                   
                                </asp:CheckBoxList>